Continuation of work funded under EY 01128-03, on spatial, temporal and chromatic interactions in vision. Using Maxwellian-view and CRT display techniques, we can produce steady and flickering gratings, homochromatic and heterochromatic flickering fields. We propose to measure psychophysical thresholds throughout the spatio-temporal frequency domain, stabilizing the stimulus pattern on randomly selected trials to explore the effects of normal eye-movements on vision. Our novel eyetracking technique will also be used to isolate the effects of retinal inhomogeneity on sine-wave thresholds. Chromatic flicker experiments will be conducted with normal and dichromatic subjects to study the properties of antagonistic pathways in the retina. Theoretical studies of pattern vision will be pursued. BIBLIOGRAPHIC REFERENCES: D.H. Kelly, Pattern detection and the two-dimensional Fourier transform: Flickering checkerboards and chromatic mechanisms. Vision Res. 16, 277-287 (1976). D.H. Kelly, R.M. Boynton and W.S. Baron. Primate flicker sensitivity: Psychophysics and electrophysiology. Science 194, 1077-1079 (1976).